I apologize for the confusion I caused by trying to piggyback my bug
report onto Mark Schwenk's.  I happened to get a walkback in the same
code location.  With the ModProjClassHack loaded, I get a walkback
elsewhere.  The debug log is at the bottom of this message.

Here's my recipe for reproducing the error:

1. Create a throwaway change set, make it current.
2. Create a new class and then remove it, leaving the (now removed)
class change in the change set.
3. Make some other change set current.
4. Try to use 'submerge into other side' with the newly created change
set as source and some other change set as target.

I guess ClassChangeRecord>>noteChangeType:fromClass: gets into trouble
because #addedThenRemoved isn't one of the toplevel choices.

Steve

PS:  I can get along fine without a fix for this.  I'm just trying to
help test this (extremely neat) new feature.

--------SqueakDebug.log--------

25 April 2000 5:17:14 am
Error: Unrecognized changeType
ClassChangeRecord(Object)>>error:
ClassChangeRecord>>noteChangeType:fromClass:
[] in ClassChangeRecord>>assimilateAllChangesIn:
[] in IdentitySet(Set)>>do:
Array(SequenceableCollection)>>do:
IdentitySet(Set)>>do:
ClassChangeRecord>>assimilateAllChangesIn:
ChangeSet>>absorbClass:from:
[] in ChangeSet>>assimilateAllChangesFoundIn:
SortedCollection(OrderedCollection)>>do:
ChangeSet>>assimilateAllChangesFoundIn:
ChangeSorter>>submergeIntoOtherSide
ChangeSorter(StringHolder)>>perform:orSendTo:
[] in MenuMorph>>invokeItem:event:
BlockContext>>on:do:
[] in BlockContext>>valueUninterruptably
BlockContext>>on:do:
[] in BlockContext>>valueUninterruptably
BlockContext>>on:do:
BlockContext>>valueUninterruptably
BlockContext>>ensure:
CursorWithMask(Cursor)>>showWhile:
MenuMorph>>invokeItem:event:
MenuItemMorph>>mouseUp:
HandMorph>>handleMouseUp:
HandMorph>>handleEvent:
HandMorph>>processEvents
[] in PasteUpMorph>>doOneCycleNow
Array(SequenceableCollection)>>do:
PasteUpMorph>>handsDo:
PasteUpMorph>>doOneCycleNow
PasteUpMorph>>doOneCycle
[] in Project>>spawnNewProcess
[] in BlockContext>>newProcess